Modern archery equipment is very complex. The bows commonly used today are capable of storing and releasing large quantities of energy. A side effect of the release of these large sums of energy is the vibrations that are passed through the bow's handle. These vibrations are generally absorbed by the arm of the user and very often effect the accuracy of his/her shooting. Additionally, the vibrations create noise that may scare prey away.
Stabilizers are known in the art for dissipating the vibrational energy associated with the use of bows. These devices are generally positioned on the bow riser and include internal mechanisms for displacing the energy before it reaches the user's arm or creates any undesired noises. They function to dissipate the energy by utilizing a variety of damping mechanisms. Stabilizers are also useful in dissipating the energy released in devices other than bows. For example, rifles and guns release large sums of vibrational energy that can be readily dissipated through the use of stabilizers.
For example, U.S. Pat. No. 4,982,719 (Haggard et al) discloses a hydraulic bow stabilizer that utilizes a hydraulic damping arrangement in combination with a pair of springs. U.S. Pat. No. 4,893,606 (Sisko) and U.S. Pat. No. 5,044,351 (Pfeifer) also disclose stabilizing devices that utilize a hydraulic dampening arrangement, in combination with a pair of springs, to dissipate any vibrational energy. Further, U.S. Pat. No. 4,570,608 to Masterfield discloses the use of a fluid filled cylinder for dissipating the energy associated with firing a bow.
In addition to the use of hydraulic dampening structures, the art is well aware of a wide variety of stabilizers having spring biased dampening structures. Exemplary of such devices are the stabilizers disclosed in U.S. Pat. Nos. 3,628,520 (Izuta), 4,245,612 (Finlay), 4,615,327 (Saunders), 4,660,538 (Burgard), and 4,986,018 (McDonald, Jr.).
The instant invention is an advancement over the prior art devices discussed above. First, the prior art devices do not disclose a stabilizer that attempts to dynamically absorb the vibrations of the stabilized instrument by approximating the frequency characteristics of the instrument to be stabilized. Second, none of the prior art devices disclose or suggest the use of a gas spring in a stabilizer. Consequently, the prior art devices fail to disclose the combination of a gas spring and an adjustable weight piston. Additionally, the instant invention requires no venting, is easy to use, and functions quieter than the prior art devices discussed above.